The post Stakeholders on St. Martin’s demand stringent action against plastic pollution appeared first on Dhaka Mirror.
]]>Stakeholders have stressed that raising awareness alone is not enough to tackle plastic pollution on the country’s only coral island, Saint Martins, and are advocating for restrictions on plastic use and penalties for non-compliance.
At a panel discussion entitled “Plastic Free St Martins” on Wednesday, they called for strict limits on plastic consumption and called for a penalty for failing to comply with the restrictions.
In the discussion held as part of World Tourism Day 2023, Shiblul Azam Koreshi, president of the Tour Operators Association of Bangladesh (TOAB), said, “The efforts aimed at increasing public awareness to combat plastic pollution have fallen short in effectively controlling this pressing issue. Both tourists and permanent residents on the island continue to use plastic, with inadequate measures in place for waste management. Although bins have been provided for separating plastic and compostable waste, there are no clear guidelines on who will remove them and where they will ultimately be disposed of. Besides, plastic pollution from fishing trawlers, including beverage bottles and chips packets, is further exacerbating the problem.”
Moreover, he pointed out a significant issue regarding the resorts on St Martin’s, with around 250 resorts operating without valid licences. He noted that residents in these resorts regularly use plastic, and there is a lack of proper directions on how to handle and store plastics. He stressed the need for specific policies and laws to be enforced to address these concerns effectively.
Tanvir Shakil Joy, a member of the Parliamentary Standing Committee on the Ministry of Environment, Forest, and Climate Change, emphasised the urgent need for improved coordination in waste management. He stressed the importance of adopting a holistic approach and even suggested considering a ban on plastic in St Martin’s.
He pointed out that the government cannot sustain waste management solely through subsidies and highlighted the potential for profitability in waste collection and recycling. He also highlighted the importance of strengthening regulations related to waste management.
Cox’s Bazar-2 Member of Parliament (MP) Asheq Ullah Rafiq proposed the introduction of travel permits for St Martin’s every two or three years to alleviate the pressure on the island. He suggested that the government take the lead in establishing a landfill on the island to effectively manage waste. He also called for regulations mandating plastic product manufacturers to label their items for recycling and proper disposal.
“Sonadia Island should be developed as an alternative tourist destination to St Martin’s,” he added, acknowledging the challenges in curbing repeated trips to St Martin’s despite efforts from the Prime Minister’s Office.
During the opening ceremony, speaker Shirin Sharmin highlighted the importance of promoting tourism while preserving ecological balance. She emphasised showcasing the natural beauty of the country to attract tourists, with initiatives to make St Martin’s and Cox’s Bazar beaches plastic-free.
She also emphasized the importance of effective implementation of government plans and their direct impact on economic growth.
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]]>The post Amazon deforestation down by a third in 2023, says Brazilian government appeared first on Dhaka Mirror.
]]>Deforestation in Brazil’s Amazon fell by 33.6% in the first six months of President Luiz Inácio Lula da Silva’s term compared with the same period in 2022, the government says.
Its suggests the rainforest shrank by 2,649 sq km this January-June, down from 3,988 sq km in those six months last year under President Bolsonaro.
The released government satellite data has not been independently verified. Lula has pledged to end deforestation, or forest clearance, by 2030.
But he faces a huge challenge to achieve this target, as the area of rainforest still reported to be lost under his rule is more than three times the size of New York City.
The past few years have seen an alarming rise in deforestation. The Amazon rainforest is a crucial buffer in the global fight against climate change.
The new satellite data was presented by Brazil’s National Institute of Space Research (Inpe) on Thursday.
“We have reached a steady downward trend in deforestation of the Amazon,” Environment Minister Marina Silva told reporters.
Inpe singled out June as the month that saw a record 41% drop in forest clearance compared with the same period last year.
Lula, who took office in January, has vowed to reverse policies of his far-right predecessor Jair Bolsonaro, who promoted mining in indigenous lands in the Amazon.
Earlier this year, Lula decreed six new indigenous reserves, banning mining and restricting commercial farming there.
Indigenous leaders welcomed the move – but stressed that more areas needed protection.
And while deforestation was reported to have fallen, fires were up in the statistics.
In June alone, satellite monitoring detected 3,075 fires in the Amazon – the highest number since 2007.
Many of the blazes – releasing vast amounts of carbon emissions – have been linked to the clearing of previously deforested areas.
Lula, who previously served as Brazil’s president in 2003-2010, has also been pushing for the world’s richest nations to pay for various initiatives aimed at saving the rainforest.
In April, research by Global Forest Watch monitoring network showed that an area of tropical forest the size of Switzerland was lost last year around the world as tree clearance surged.
It said that some 11 football pitches of forest were lost every minute in 2022, with Brazil dominating the destruction.
It suggested that a political pledge to end deforestation made by world leaders at the UN Climate Change Conference in Glasgow in 2021 was well off track.
The Amazon is the largest rainforest in the world, and 60% of it is in Brazil.
Due to the large number of trees growing there, it is often called “the lungs of the planet” on account of how the trees absorb carbon dioxide and release oxygen.
– Article originally appeared on BBC
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]]>The post Half of world’s largest lakes, reservoirs losing water, Study finds appeared first on Dhaka Mirror.
]]>More than half of the world’s largest lakes and reservoirs have lost significant amounts of water over the last three decades, according to a new study, which pins the blame largely on climate change, intensifying concerns about water for agriculture, hydropower and human consumption.
According to a team of international researchers, some of the world’s most significant freshwater sources -from the Caspian Sea between Europe and Asia to South America’s Lake Titicaca have been losing water at a cumulative rate of roughly 22 gigatonnes per year for almost three decades.
That is about 17 times the volume of the largest reservoir in the United States – Lake Mead.
The study published in the journal Science found unsustainable human use dried up lakes, such as the Aral Sea in Central Asia and the Dead Sea in the Middle East, while lakes in Afghanistan, Egypt and Mongolia were hit by rising temperatures, which can increase water loss to the atmosphere.
Water levels rose in a quarter of the lakes too, often as a result of dam construction in remote areas such as the Inner Tibetan Plateau.
Natural lakes and dams store about 87 percent of the Earth’s freshwater, although they cover just 3 percent of the planet’s surface. The report was based on satellite image data collected between 1992 and 2020.
Fangfang Yao, a surface hydrologist at the University of Virginia who led the study, said 56 percent of the decline in natural lakes was driven by climate warming and human consumption, with warming “the larger share of that”.
Climate scientists generally think that the world’s arid areas will become drier under climate change, and wet areas will get wetter, but the study found significant water loss even in humid regions.
“This should not be overlooked,” Yao said.
Scientists assessed almost 2,000 large lakes using satellite measurements combined with climate and hydrological models. They found that unsustainable human use, changes in rainfall and run-off, sedimentation, and rising temperatures have driven lake levels down globally, with 53 percent of lakes showing a decline from 1992 to 2020.
Spain recently reported that reservoirs in the northeastern region of Catalonia are about 26 percent full after months of drought. In comparison, that figure was 58 percent full in 2022.
In Italy, unusually low water levels were recently recorded for Lake Garda compared with the same period in 2022. The water level was 50 percent lower compared with the previous year.
Scientists and campaigners have long said it is necessary to prevent global warming beyond 1.5 degrees Celsius (2.7 degrees Fahrenheit) to avoid the most catastrophic consequences of climate change. The world is currently warming at a rate of approximately 1.1C (1.9F).
– Input from News Agencies was used in this article.
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]]>The post Waterways disappear as rivers die appeared first on Dhaka Mirror.
]]>Rashad Ahamad
Inland waterways, once the prime mode of transportation in Bangladesh, have declined fast as many rivers, canals, and other water bodies have disappeared in riverine Bangladesh over the past decades.
Due to geographical location, inland waterways were the main mode of transportation in Bangladesh, a country part of the largest delta in the world, but that mode has changed due to erroneous policies in communication development, experts said.
The authorities had destroyed the popular, cheap and safer waterways and instead had expanded only road transportation, facilitating the deaths of many rivers, they said.
In this context, World River Day will be observed across the country today. The day is observed across the world on the fourth Sunday of September.
The River and Delta Research Centre chairman, Mohammad Azaz, blamed river grabbing and pollution, water scarcity from upstream and climate change for decreasing water transportation in Bangladesh.
Khalid Mahmud Chowdhury, state minister for shipping, claimed that governments after 1975 followed a wrong transport development policy, allowing waterways to shrink.
He claimed that successive governments’ ‘business-oriented transportation plan’ prioritised the road while ignoring rail and waterways.’
He stated that Bangladesh used to have 24,000 kilometres of waterways, but this number has now drastically decreased.
‘Awami League government is now working to make 10,000 km of waterways as per our election pledge,’ he said.
He also said that they had dredged 53 rivers already and that the dredging work in some rivers was in progress as the government had bought 50 heavy dredgers and initiated the process of procuring 35 more. Several sea ports and 35 river ports were upgraded.
The government has adopted the Delta Plan 2100 with a special focus on rivers.
Bangladesh Inland Water Transport Authority statistics showed that in 1975, there were 223 river routes and about 8,489 kilometres of navigable waterways in the rainy season in Bangladesh and 5,287 kilometres in the dry season.
At present, about 5,900 kilometres of waterways are navigable in the rainy season and only about 3,800 kilometres of waterways are navigable in the dry season on 188 routes.
Amid the reality, Bangladesh is set to observe World River Day with the theme ‘Waterways in Our Community’ emphasising both protecting rivers and restoring waterways.
RDRC chairman Azaz said that over 500 rivers in the country disappeared in the past 50 years, while the number of canals that disappeared was much higher, with no study available.
The National River Conservation Commission reported 770 rivers across the country. According to RDRC, the number was 1,274 during the war of independence in 1971.
Jahangirnagar University urban planning professor Adil Mohammad Khan blamed professionals for accepting the wrong development policies of the government and development partners.
‘Just see, in Dhaka, box-culverts were made by blocking canals,’ he said, citing an example.
He also said that many unnecessary roads were constructed in the haor areas, where people once mostly used boats for transportation.
‘Embankment to control flooding also restricted vessel movement,’ he said.
He said that as rivers were not in use, they lost navigability, were grabbed, polluted and eventually died.
Green activists said that the Local Government Engineering Department and the Roads and Highways Department have constructed most of their bridges and culverts, narrowing rivers and decreasing navigability.
Flat bridges and culverts restrict boat movement in local waterways.
Abdus Sattar, once a boatman who used to carry goods from Ghatail in Tangail to different destinations including Mymensingh, Dhaka, and Narayanganj, said that after the construction of a low-height flat bailey bridge on the Jheenuk River, he had to sell his boat as he couldn’t move under the bridge.
The Jheenuk River, a branch of the Jamuna River, flowing over Bhuyapur and Ghatail, is now all but dead. There is no water flow in the river in the dry season. Domestic and industrial waste polluted the river, where hardly any fish is now available, said Sattar.
‘I made my living as a boatman until the bridge came here in 1995. I tried to remain in the profession even after few more years. Later, I switched to farming,’ said Sattar.
The LGED claims to have built 36,311 bridges to complete its 330,831 kilometres road network across the country, while the RHD claims to have built 4,404 bridges and 14,814 culverts in its 22,418 km length of 992 roads.
Green activist M Hamid Ranju said that he used to go to Mirpur in Dhaka from Genda of Savar by boat even in the 90s, carrying goods with other traders.
He said that his mode of transportation has changed since Bill Bagheel choked and dried out being left uncared for and the expansion of the Dhaka-Aricha Highway.
He said that at one time, every family in his area owned at least one boat. Now motorcycles or cars have replaced boats in many families.
The National River Conservation Commission chairman, Manjur A Chowdhury, said that alongside illegal grabbing and earth-filling, some transboundary issues were also behind the death and disappearance of rivers and waterways in Bangladesh.
He explained that many rivers were silted for lack of water as the water flow was restricted upstream.
The commission has identified 60,000 river grabbers so far across the country.
Bangladesh Environmental Lawyers Association chief executive Syeda Rizwana Hasan said that in the name of road network development, the rivers and canals were killed in a planned way.
Professor Emeritus and river expert Ainun Nishat said that any action that harms the river and its natural environment was illegal and also a violation of the constitution.
‘But it is happening continuously,’ he said. ‘The officials of LGED and RHD responsible for the action should be brought to book,’ he added.
The Bangladesh Poribesh Andolon general secretary, Sharif Jamil, said that if the waterways could be protected, the rivers and canals would remain protected.
‘A river is part of an ecosystem. It is a lifeline, a livelihood and many more. With the death of many rivers, everything collapsed,’ he said.
Article originally published on New Age
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]]>News Desk : dhakamirror.com
Chattogram city produces 249 tonnes of plastic waste every single day — 56 percent of which remains uncollected and littered in the environment, according to a new study.
“Of the plastic waste, the most are sachets, single-use utensils, and personal care items, ” the study added.
The port city will generate 428 tonnes of plastic waste by 2052, according to the study conducted by the Civil Engineering Department of Chittagong University of Engineering and Technology (CUET).
The findings of the study were disseminated today (September 10, 2022) at a press conference at Chattogram Press Club, reports our local staff correspondent.
Swapan Kumar Palit, professor of the Civil Engineering Department of CUET and also the supervisor of the study, stated that an integrated waste management system is very important.
The survey for the study was conducted among 75 retailers, 75 waste pickers and a few manufacturers in the port city.
Plastic waste has harmful effects on the environment, society, economy and health, the study revealed.
This study also suggested making bitumen out of plastic waste and making roads out of it.
Former vice-chancellor CUET Jahangir Alam, environmentalist Dr Idrish Ali, General Secretary of Bangladesh Environment Forum Aliur Rahman attended the press conference.
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]]>The post Non-stop river pollution threatens water security appeared first on Dhaka Mirror.
]]>Non-stop river pollution threatens water security
Laws, rules, HC directives go in vain
Rashad Ahamad
No pragmatic step is yet to be taken to protect the four rivers surrounding Dhaka even after declaring them ecologically critical 13 years ago.In September 2009, the Department of Environment declared the four rivers Ecologically Critical Areas under Section 5 of the Bangladesh Environment Conservation Act. There are total 13 ECAs in Bangladesh.
The government formulated the Ecologically Critical Areas (ECA) Management Rules 2016 for implementing the act, including restoring and protecting the ecology of the endangered ECAs.
As inaction by the government agencies concerned drags on, the pollution of the Buriganga, the Turag, the Balu and the Sitalakhya has been intensifying, risking the water security of some 20 million people of the capital city of Bangladesh, the world’s largest delta, said green activists.
Environment minister Shahab Uddin, however, said that the environment department was struggling to protect the rivers with its limited manpower, but, he added, its efforts cannot succeed without cooperation of other ministries.
National River Conservation Commission chair Manjur Ahmed Choudhury said that he did not see any pragmatic step taken by the DoE as the agency did not even form a committee to work out a plan of action to restore the ecology of the rivers, a measure mandatory according to the 2016 rules.
Manjur said that not only the four rivers around the capital but most of the rivers across the riverine country were now in a critical condition due to pollution and grabbing.
On the occasion of World Environment Day today, a coalition of environment advocacy organisations has arranged a mass bathing in the Buriganga to press the demand for ensuring fresh water in the river by checking all sorts of pollution so that people can use the river water without any harm caused to them.
The government and various NGOs have also chalked out numerous programmes marking the day.
The UN Environment Programme has set the theme for this year’s World Environment Day as Only One Earth: Living Sustainably in Harmony with Nature. We need to save this world, save all kinds of animals, plant more trees.
NRCC chair Manjur Ahmed at an event on the day at the National Press Club in the capital on Saturday said that the water of the rivers around Dhaka became toxic because of pollution.
‘If anyone falls in these rivers in March and April they will die not for the inability to swim but for the toxicity of the water,’ he added.
The river water has become a death threat for people, he further said.
Green activists and researchers blamed the Dhaka WASA as the top responsible agency for the pollution caused mainly by industrial and municipal wastes.
DoE officials, quoting lab test reports, said that the water quality of the four rivers had been remaining so bad for eight months between October and May for years that aquatic life could not survive in them.
According to a lab report, the Buriganga water’s biochemical oxygen demand, or BOD, stood at between 15 and 20 and dissolved oxygen, or DO, at zero while the BOD standard is below six and the DO value should be more than 5 in any surface water body.
Dhaka WASA managing director Taqsem A Khan said that the agency was diverting its water intake point to the Meghna and the Padma as the Sitalakhya and Buriganga water was now not treatable due to the extreme pollution.
The water pollution in the Buriganga and the Sitalakhya, he said, is so acute that their water cannot be treated for several months in the dry season.
As the water of the rivers is no more treatable, the lone water supplying agency will collect water from the Padma, 33 km away from the city, and the Meghna, 22 km away, he said.
Bangladesh Poribesh Andolon executive vice-president Abdul Motin criticised the Dhaka WASA plan as he blamed that the agency itself was polluting the rivers.
‘It is a ridiculous plan of the Dhaka WASA to collect water from the Padma and the Meghna instead of stopping the water pollution in the nearby rivers,’ he said.
Institute of Water Modelling executive director Abu Saleh Khan said that the water security of the people living in the capital city and some other parts of the country is gradually becoming more and more challenging due to unabated pollution.
‘We are fortunate as we have vast water, but we are very unfortunate as we cannot protect water from pollution,’ he said.
He cautioned that if the water pollution was not stopped water security would be at risk not only in Dhaka but across the entire country.
Donors, he noted, are now worried about investing even in the Meghna water treatment plant due to pollution.
Industrial units are dumping untreated effluents in the rivers to save money even though they have treatment plants, Abu Saleh resented.
Environment minister Shahab Uddin admitted that some factories were involved in this practice, adding that the DoE has limited manpower for monitoring the factories regularly and for bringing the errant industries to book.
‘We are working to bring the effluent treatment plants under an online monitoring system,’ he said.
A research published on the ScienceDirect website in February 2021stated that more than 7,000 industrial units in Hazaribagh, Tejgaon and Dhaka-Narayanganj-Demra areas discharged some 60,000 cubic metres of toxic waste-water into the four rivers every day.
The unavailability of treatable surface water is also prompting the Dhaka WASA to dig deeper for water, risking both the quantity and quality of ground water as the acquirer continues to decline.
Taqsem admitted that Dhaka WASA collected 20 per cent of the total sewage generated in Dhaka but denied the responsibility for the rest.
‘Households will manage their waste by themselves as the Dhaka WASA does not collect any bills from them for the purpose,’ he explained.
However, he said that five sewage treatment plants were under construction according to the Dhaka WASA sewage master plan.
Once the plants start operating by 2030 no sewerage will fall into the rivers, he said.
NRCC chair Manjur also said that the NRCC was working with the Bangladesh University of Engineering and Technology to develop a model of water treatment that would release clean water into the rivers after treating polluted water in canals.
Thereafter, the government had taken some steps but except relocating the tanneries from Hazaribagh to Savar in 2017 and demarcating rivers no othersteps were implemented fully.
BAPA general secretary Sharif Jamil said that the tanneries were now polluting the Dhaleshwari River in Savar, upstream of the Buriganga.
The government in 2009 also formed the high-powered National Taskforce to Protect Rivers and the National River Protection Commission for saving not only the four rivers but all rivers of the country. The taskforce is now almost inactive.
The High Court in July 2019 declared all rivers as living entities, observing that the country will survive if the rivers are protected.
Green activists said that even after having many laws and HC directives the government was not sincere in saving the rivers of the country.
‘Without political commitment, river pollution and encroachment cannot be stopped,’ said MA Abdul Matin, a former BAPA president.
– Article originally published on New Age
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]]>The post Air pollution takes 3 years off life in Bangladesh appeared first on Dhaka Mirror.
]]>Mohammad Al-Masum Molla
Air pollution cuts the average life expectancy of a person in Bangladesh by almost three years, said a global report.It is higher than in India, Pakistan, Bhutan, and Afghanistan. Nepal, with air pollution-linked life expectancy loss of 3.05 years, is the worst affected in this region, according to the report released yesterday by US-based organisations Health Effects Institute and Institute for Health Metrics and Evaluation.
The report, titled “State of Global Air-2020: How Does Air Pollution Affect Life Expectancy around the World”, said air pollution’s impact on life expectancy is the greatest in less-developed countries, where many suffer a double burden from high outdoor and indoor air pollution.
The worst affected countries included Papua New Guinea (3.2yrs) and Niger (3.1yrs), said the report, prepared based on air quality data collected from across the world in 2019.
For Bangladesh, the life expectancy loss is 2.91 years, said the report, which added that 1.16 years is cut short by outdoor air pollution while 1.53 years by indoor air pollution.
At present, the average life expectancy of Bangladeshis is 72.6 years, according to the Bangladesh Bureau of Statistics.
The current levels of air pollution have reduced the global life expectancy by one year and eight months on average, the report also said. “Air pollution reduces people’s average life expectancy by almost as much as tobacco use does.”
The poor air quality of Bangladesh often makes global headlines due to fossil fuel combustion, biomass burning, emissions from unfit vehicles, brick kilns and massive development works.
The World Air Quality Report 2020, released in March last year, said the average annual PM 2.5 concentrations in the country was 77.1 micrograms per cubic metre, which was more than two times higher than the WHO recommendation.
A 100 percent of Bangladesh’s population is in areas that exceed the annual WHO guideline for the least stringent interim target of 35 micrograms per cubic meter, it said.
Particulate matter (PM) is the sum of all solid and liquid particles suspended in air, many of which are hazardous. This complex mixture includes both organic and inorganic particles, such as dust, pollen, soot, smoke, and liquid droplets.
To estimate the impact of a particular factor on life expectancy, researchers quantify the likelihood of dying from diseases related to that factor at different ages in a population and calculate a “risk-deleted” life expectancy — that is, the length of life that would be expected if the factor were absent.
According to the World Health Organisation, air pollution kills an estimated seven million people worldwide every year.
Pallavi Pant, senior scientist at Health Effects Institute, told The Daily Star, “The burden on health due to air pollution is massive across South Asia, and we see that both in terms of deaths and reduction in life expectancy as well as the economic costs.”
She also said, “Currently, most countries in the region do not even meet the least stringent target values for PM2.5 or ozone. Data shows that there is a need to prioritise long-term reduction of emissions from major sources of air pollution. In doing so, the WHO guidelines and Interim Targets can serve as useful milestones
or benchmarks.”
As his attention was drawn to the report, Prof Abdus Salam of Dhaka University’s chemistry department, said, “It is an established fact that air pollution reduces people’s life expectancy. The report has also shown us that checking outdoor air pollution is as important as curbing indoor pollution.”
Article originally published on The Daily Star
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]]>The post Rain at the summit of Greenland for the first time on record appeared first on Dhaka Mirror.
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Something extraordinary happened recently. On August 14, 2021, it rained at the highest point on the Greenland Ice Sheet for several hours — the first rainfall event in recorded history, and air temperatures remained above freezing for about nine hours.The record-breaking rain is the latest in a string of warning signs about how climate change is affecting Greenland’s ice sheet.
Scientists confirmed these sightings on August 18th that rain were observed Saturday at Summit Station, a research facility that sits atop the Greenland ice sheet and is operated year-round by the National Science Foundation. It was the first report of rain at the normally frigid summit, and it marks only the third time in less than a decade that above-freezing temperatures were recorded at the Arctic research station, according to the National Snow and Ice Data Center.
About 7 billion tonnes of rain fell on the ice across Greenland over three days, from 14 August through 16 August- the largest amount since records began in 1950. This is the first rain since the country’s meteorological record began in 1950. Unusual rainfall is evidence that temperatures in Greenland are rising.
The recent warm spell adds to concerns that climate change is rapidly melting ice in the Arctic, which accelerates sea-level rise around the world.
This unprecedented episode is on top of the most recent heat wave that struck Greenland in July, losing more than 8.5 billion tons of surface mass in a single day. This increases concerns about the acceleration of rising waters around the world.
The consequences of that would be catastrophic. If Greenland’s ice sheet were to completely melt, scientists have said global sea levels could rise more than 20 feet, affecting coastal communities and submerging low-lying cities around the world.
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]]>The post Emissions of CO2 driving rapid oceans ‘acid trip’ appeared first on Dhaka Mirror.
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The world’s oceans are becoming acidic at an “unprecedented rate” and may be souring more rapidly than at any time in the past 300 million years.In their strongest statement yet on this issue, scientists say acidification could increase by 170% by 2100.
They say that some 30% of ocean species are unlikely to survive in these conditions.
The researchers conclude that human emissions of CO2 are clearly to blame.
The study will be presented at global climate talks in Poland.
In 2012, over 500 of the world’s leading experts on ocean acidification gathered in California. Led by the International Biosphere-Geosphere Programme, a review of the state of the science has now been published.
This Summary for Policymakers states with “very high confidence” that increasing acidification is caused by human activities which are adding 24 million tonnes of CO2 to oceans every day.
Pickled waters
The addition of so much carbon has altered the chemistry of the waters.
Since the start of the industrial revolution, the waters have become 26% more acidic.
“This is the state of the art,” said Prof Jean-Pierre Gattuso, from CNRS, the French national research agency.
“My colleagues have not found in the geological record, rates of change that are faster than the ones we see today.”
What worries the scientists is the potential impact on many ocean species including corals.
Studies carried out at deep sea vents where the waters are naturally acidic thanks to CO2, indicate that around 30% of the ocean’s biodiversity may be lost by the end of this century.
These vents may be a “window on the future” according to the researchers.
“You don’t find a mollusc at the pH level expected for 2100, this is really quite a stunning fact,” said Prof Gattuso.
“It’s an imperfect window, only the ocean’s acidity is increasing at these sites, they don’t reflect the warming we will see this century.
“If you combine the two, it could be even more dramatic than what we see at CO2 vents.”
The effect of acidity is currently being felt most profoundly felt in the Arctic and Antarctic oceans. These chilly waters hold more CO2 and increasing levels of the gas are turning them acidic more rapidly than the rest of the world.
The more acidic they become, the more damaging they are to the shells and skeletons of marine organisms.
The researchers say that by 2020, ten percent of the Arctic will be inhospitable to species that build their shells from calcium carbonate. By 2100 the entire Arctic will be a hostile environment.
These effects are already visible says Prof Gattuso.
“In the Southern Ocean, we already see corrosion of pteropods which are like sea snails, in the ocean we see corrosion of the shell.
“They are a key component in the food chain, they are eaten by fish, birds and whales, so if one element is going then there is a cascading impact on the whole food chain.”
The authors warn that the economic impact of the losses from aquaculture could be huge – the global cost of the decline in molluscs could be $130bn by 2100 if emissions of CO2 continue on their current pathway.
Adding alkaline substances such as crushed limestone to the waters has been mooted as a potential way of mitigating the worst impacts of acidification. But Prof Gattuso says it would only have a limited effect.
“Maybe in bays which have a restricted exchange with open oceans it may work, it may give some local relief.
“But the latest research is showing that it is not really practical at a global scale. It is very expensive and very energy intensive.”
Marine protection zones would also give some short term benefit, but the scientists say that in the long term only significant cuts in emissions will slow the progress of acidification.
-With bbc.co.uk input Image Courtesy: SPL
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]]>The post Warming trees limit warming – a little appeared first on Dhaka Mirror.
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Warmer temperature prompts trees to release aerosols which in turn stimulate cloud formation. And that can help to cool the temperature, at least modestly.Trees may provide the Earth with a little shade from global warming – indirectly. European and Canadian researchers report that they have found what engineers like to call a negative feedback loop above the forests of Europe and North America.
It works like this. Trees – those natural chemical factories that routinely deliver complex aromatic compounds such as rubber, coffee, chocolate, resins, pungent fruits, oils and natural drugs such as quinines – are a permanent source of volatile organic compounds released into the atmosphere.
On a hot day, trees release even more conspicuous quantities of terpenes, isoprenes and other compounds into the air. These are wafted higher in the atmosphere and begin to mix, oxidise, or chemically react with other atmospheric gases, aerosols and car and factory exhausts to form increasingly larger particles on which water vapour might condense.
This is not a new observation. The Smoky Mountains of Tennessee and North Carolina take their name from the pall of isoprenes discharged from the oaks that cover the hills: the mountains actually look smoky, according to a Climate News Network report.
The aerosols from trees float in the atmosphere and reflect and scatter sunlight and even form cloud droplets. So far, so familiar.
But Pauli Paasonen, of the University of Helsinki and the International Institute for Applied Systems Analysis in Laxenburg, Austria, writes in Nature Climate Change that he and 23 colleagues in Finland, Sweden, Germany, Canada and the US decided to assess the overall effect of these aerosols and their contribution to, or impact upon, global warming.
Every little helps
They analysed data from eleven measuring stations spread across the northern hemisphere, from semi-Arctic wilderness to polluted agricultural lands, and worked out how the quantities of cloud condensation nuclei might be linked to air temperatures.
They found a clear connection. The warmer the weather, the greater the likelihood that gas emissions from plants would create conditions for the formation of clouds, which in turn would reflect more sunlight back into space, and thus help damp down global warming.
That is the good news. The not-so-good news is that these plant gas emissions won’t make a great deal of difference – on a global scale they might counter about 1% of global warming.
On a regional scale, however, the effect might be much greater: in heavily forested areas – Finland, Siberia and Canada, for instance – where human emissions of aerosols are anyway relatively slight, plant gas releases might counter as much as 30% of warming.
The effect however was not easy to predict, and may not be easy to confirm. The key variable is the boundary layer of the atmosphere at which gases and particles mix and form the nuclei around which cloud droplets might condense, and the height of this boundary changes with weather conditions.
“Plants, by reacting to changes in temperature, also moderate these changes”, says Dr Paasonen. “One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do.”
Courtesy of unbconnect.com
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